Back gauge for punches



July 12, 1938. G1' H. DAwsoN 2,123,170

BACK GAUGE Fon PuNcHEs .Filed sept. 19, 1 934 `2 Sheets-sheet 1 l INVENTOR. E 650,965 H. DAM/50N /4 /5 BYZ -Vi ATTORNEY.

July 12, 1938;.. G. H. DAwsoN BACK GAUGE FOR PUNCHES Filed Sept.Y 19, 1954 2 sheets-sheet 2 INVENTOR. 650965 H. D/IWSO/V n. N m T T. A

Patented July 12, 1938 N UNITEosTArES PATENTy voFF-ice Y "2,123,170 Y Y l BACK'GAUGE FOR PUNCHES George Dawson, Chicago, lll., assigner to WilSon-JcneSQCGmpany, Chicago, Ill., a corporation of Massachusetts n Application September 19, 1934,` Serial Nc. 744,629

` etonne-'si (cl. ien- 91) This invention'relates toa gauge for punches by means of which thedistance1between the `punching and the back edge of the punched sheets may be regulated. 1 1

It is an object of this `invention to provide a simple and eicient gauge that may be easily and accurately adjusted, without the use of any tools, to regulate the distance a sheetof material to be punched may be inserted into the mouth of the punch. It is a further object `oi thisinvention to provide algauge that will stayin any position to retain the exact adjustment desired. It is a further object of this invention to provide a gauge mounted on the base of the punch, rather than on the punch head, so that only `two gauges will be required for any punch, regardless of the number of punch heads on the punch. Other objects of this invention will become apparent upon reading the following description taken `in conjunction with the accompanying drawings, in

which f Figure 1 is a perspective view of a punch em- `loodying the invention;` I

. Figure `2 is a fragmentary top plan view oi one end of` the punch shown in Figure l;-

Figure 3 is a cross `sectional view taken on the line III-III of Figure.2,lookingin the direction of the arrows, with parts broken away` to facilitate illustration of the structure; ,I I

Figure 4 is a Across Vsectional View .throughf a different type of punch showing a modied--form 0f back gauge? i@ 5 Figure 5 is a view si lar,toFigure 4 j,showing another modified formpi-back gauge; ,i

Figure 6 is a cross sectional View of the punch of` Figures 1 to 3, showing a modiiied form of back gauge; and

Figure '7 is a View similarv to Figure 6 showing another modified form of back gauge. A

In the drawings, the referencenumeral.2y in dicates a base member provided witha `removable chip pan 3. The chip pan-is provided with a covering'd of felt or similarmaterialto provide `an attractiveappearance and to protect thefiinish on any surface on which thepunch mightv be handled. The side walls 50i the base extendat a slight angle from the vertical, as` shown in Figure 3, andthe edges 6 of the'chippanfare bent so as to provide a'resilientvr engagementibetween the chip pan and the base.

, The base member. 2 is-provided at `each fend with an` integral upstanding ear 8. Ahollow rod 9 is supported in apertures positionedadjacent the rear of the ears 8. A wire I0 Vof any desired conguration may be positioned within the hollow rod 9. The end II of the wire Il] is bent to form a side gauge for the punch. The wire It) is secured within the rod in any desired position by means of a thumb screw I2.

The rod 9 also helps support a plurality of `It of the punch heads.

shape.

punch heads I3. The top surface I ofthe base is provided with a ledge I5, Figure 3, to support thekfront end I5 of each punch head. Another ledge I1, positioned at the rear of the base memrtl ber 2, has its forward edge terminating adjacent @15 a scale Iii and any suitable'identication means The punch heads I3 are slidable along the rod 9 and may be secured in any desired position by means of thumb screws ZI. The punch heads may be marked, as indicated at 22, to facilitate proper positioning with respect to the scale I9. f l

Each punch' head is provided with a. punching pin 23 having its cutting edge of any desired The pin 23 fits in a recess 24 having a portion .25 of reduced cross sectional area. The lower portion 26 of thepunching pin is reduced in cross sectional area to iit the restricted passage 25. A coiled spring 21 encircling the reduced portion 26 of each punching pin bears against the larger portion of thepin and against the shoulder 28 to exert a constant force tenda mouth or jaw into which the sheets to be punched are inserted. The distance the sheets travel into the mouth determines the spacing of the apertures punched from the edge of the paper. A pair of` back gauges 3U, spaced a suitable distance apart, regulate the distance the sheets to be punched may be inserted into the mouth of the punch heads.

The back gauge 3i! includes a flat strip of metal bent to form a horizontal portion 3I lying against the upper surface of the `flange II, a curved portion 32, a second horizontal portion 33 having a semi-circulary depression 34 fitting around the lower half of the hollowrod 9, and a vertical por- The plate I8 may carry 4,

tion 35 having its lowerl end positioned adjacent the iront surface oi the flange I'I. A flatmetal plate 36 is welded to thevertical portion 35 to increase the effective thickness of the vertical por- The portions 32 and 35, 36 are provided with registering threaded apertures to permit a screw 31 to extend therethrough. The screw 37 is provided at one end with a knurled head 3B and at the other end with a flat disk 39 permanently secured thereto in any suitable manner. The disk 39 is in the same horizontal plane as the mouth 29 of the punch heads. Rotation of the screw 31 moves the disk 39 forward or backward to. regulate the distance sheets may be inserted into the mouth of the punch heads.

' The metal plate 36 may be welded to either' side of the vertical portion 35. The end of the screw 31 projecting beyond the curved portion 32 is preferably provided with a lock nut 36. However, the lock nut may be omitted if the portion 35 has suiiicient thickness, becausethe resiliency of the metal of which the back gauge is formed will generally be sucient to retain the screw 31 against accidental rotation.

The punching pins 23 are operated 'simultaneously by pressure on a single'lever 40 secured to one end oan operating shaft 4| which passes through eachpunch head I3 and f'the'two, up- Vstanding ears 8. vIhe lever 40 `retainsone -end of the shaft-4| in position. 4The other end of the shaft `4| is secured by means of `alatch Ik12 pivoted to'the adjacentear 8 by means of' a screw 43. The shaft '4| is provided-with a longitudinal notch 44 adapted to Aengage-a projectionl45on each punch head to force Y the punching lpin through the passage 25 across the slot 29 to vperfor-ate any sheets `positioned inthe1jaw-of the punch. The lower end of the passagef25 is pref- -erably slightly enlarged, as indicated at V25', 'Figure `3, toenable the punchings to'fall through into the chip pan. When the lever 40 is released after the punching operation, the spring 21 forces the-punching pins upwardly'into position for the next punching operation.

In Figure 4I have illustrated amodied form of back gauge particularly suited for large punches,'where the distance from the-back of the punchtothe inner end` of the sheet receiving jaw is considerably greater than in the punch illustrated in Figures l'to 3. Referring' to Figure '4,a punchfbase 46"has two bars 41 and "48 extending across one edge of thepunch. Thesebars help to support a plurality ofpunchheads 49. "A plate 50.coversthe frontend off the punch heads. A suitable scale is preferably `provided'on the'surface of the plate 50 adjacent'the end of .the punch heads. The'operation of the punching structurels the. same .asthat of Figuresv 1 to' '3. Accordingly, itis believed tofbe unnecessary to describe the punching. mechanism in detail.

The back. gauge comprises a 'hat strip of metal bent to provide a pair of spaced vertically extending portions 5| andl52. The end of theportion`5| is bent into a horizontal-plane, and rests on the bar 48, as indicated at 53. .The horizontal portion' .54 connecting the upper ends of the portions 5| and`52 has .a semi-circular depression to receive a rod .56 similar to the rod'9. The

`pan J3. portion33, 'connectsl-the upper ends `of the legs "65=and'166. "I'hefront surfaceof the leg66 is'reeliminate any possibility of accidental movement of the screw by providing a lock nut between thehead of the screw and the,.portion 5| of the back gauge.

In Figure 5 the back gauge comprises a single 5 flat strip of metal 6| having one end resting on vthe bar 41 and its other end bent to form a ver- .tical portion '.-62 and a horizontal portion 63 t- .ting under the rod 56. An angular metal piece 64, of suitablev thickness, has one leg welded to the Vstrip 16| and the other extending upwardly to receive the screw 59.

Figuresl and`1illustrate modied forms of back gauges suitable for use with the punch illustrated in Figures 1 to 3. In these modica- 15 .ti'onsJ the onlydilerence. isinthe specific means :for supporting the: screwf31. In Figure 6 na flat vstriphas one vertical legY resting on the ledge |1 and another vertical leg 66 resting on the chip Afhorizontallportion 61, similarto the 20 inforced by `a relatively Ythick metal plate '68 f-welded thereto.

Innthemodied'formillustrated in Figure '1, 25

-a casting'; of any-suitable shape, is substituted Yfor'the bent metal ystructure of the other embo'diments "Although'I have described several embodiments of Vmy invention indetail, it willfbe understood 30 lthat thedescription thereof is illustrative, rather than restrictive; as many details may be modied orchangedewithout departingffrom the spirit or scope of my invention. Accordingly, I do not desire to'belimited-'to-the'fexact constructionv de- 35 scribed, except as limited by the appended claims.

1I claim:

1. In a punch, a bent stripfof metal resiliently held;againstzaflateral-movement, a screw threaded throughf portions of-saidlstrip, and a at disk ,-519

Asecured to one'en'df of fsaid screw.

2."'Ina-'punch,=apunch headprovided with a jaweadapted to=receive--sheets to be punched, la

resilient strip of -metal-secured to saidl punch indepen'dently ofsaidfpunch'head, a screw thread- ,45

:ed through said strip; and an enlargement onone end of said screw adapted to limit the distance sheetsrmay be insertedA into said jaw.

3. In a punch, apunchhead provided-with a ja-W adapted to receive'sheets to *be punched, a ;50

vrod-` extending the length of said punch, fand a back gauge supported between said rod and the basefof sai'd'punch` independently of said punch. head.

*4. Inca-"punch,"a'baseY member, a pair'ofupf55 standing-ears 'on saidbase, a rod supported by saidears, and'a'resilient back gauge supported 'by said 'base and `saidA rod.

and `a backj'gauge having one end rsupported'between `said-one support and' said rod,'the'other en'd'of sai'd'back 'gaugebeing supported on said other support. 

